Assessment of cadmium toxicity and its possible effects on goldfish (Carassius auratus), employing microscopy and biochemical techniques

Abstract

The present study aimed to evaluate and compare the toxicity level of dietary and waterborne Cadmium (Cd) source on the Goldfish Carassius auratus (C. auratus) using various biochemical and microscopic shreds of evidence. C. auratus were divided into two groups based on Cadmium supplementation methods subjected to the same concentrations in the diet and water; moreover, control (Ctrl) group was set up for comparison. Dietary supplemented group (DSG) group and (Aqueous supplemented groups) ASG were supplied with 0.5% of the Cadmium. Successful completion of the study resulted in the lucrative outcomes, and we noticed significantly high concentrations of Cadmium in the gills of the ASG fish while considerably low levels in the gills of DSG. Histopathological evidence showed clear and distinct changes in the liver cells, dilated sinusoids and unusual occurrence of Kupffer cells were noticed in the AS group fish. At the same time, there were also noticeable changes in the DS group compared to CTRL. Visible changes can be seen on the outer morphology of gills, lamella of ASG and DSG both were shrunk and broken, similar changes were noticed in the muscles myoepithelium. The stress parameters were differentially expressed in both the groups; waterborne Cadmium caused a pronounced release of AST, ALT, cortisol, and glucose concentrations. Comparative mortality showed the highest death rate in the ASG fish compared to DSG fish. The present study depicts the highest toxicity of Cadmium in the soluble Addendum form moreover, administered route and time length are crucial factors.

Toxic Effects of Cadmium on Fish

“…With the increase in Cd concentration, the degree of irreversible damage to the structure of fish liver cells also increases significantly, which mainly includes endoplasmic reticulum expansion, nuclear deformation, nuclear membrane mitochondrial swelling, distortion, granular cytoplasm, and cell edema and cavitation. When the liver tissue structure is destroyed, the detoxification ability of the liver is significantly reduced, which has an irreversible impact on growth, reproduction, and survival [ 17 , 95 , 96 ].…”

“…If fish are exposed to Cd pollution for a long time, their different tissues will absorb and accumulate Cd, thus affecting the structure and function of the gills, liver, and gonad. Furthermore, Cd affects their physiological metabolism and reproductive and immune systems and eventually leads to metabolic disorders, physical disorders, or even death [ 16 , 17 , 18 ]. Recently, studies have shown that Cd can induce various epigenetic changes, thus, changes occur in the chemical modification of DNA, histones, and chromatin, but not the sequence of DNA nucleotides, including DNA methyltransferase, histone acetyltransferase, histone deacetylase, histone methyltransferase, and microRNA.…”

Cadmium-induced DAG-PKC/IP3-Ca2+ double signaling pathway and cell injury in gill of freshwater crabs Sinopotamon henanense

“…Adding Cd 2+ to the dietary and water not only leds to distinct damages to the outer skin, scales, and gills of gold sh, but also causes inner damages in different organs such as gills lamella shrunk and broken, the necrotic muscles myoepithelium along with disrupted muscles bundle, and abnormal dilations in the liver cells (Noor et al 2020). Cd 2+ also caused the decrease of respiratory function in the freshwater crab Barytelphusa gureini, gill hyperplasia and degenerative changes in visceral organs, elevation in MDA and attenuation in GSH activity in Oreochromis niloticus (Abu-Elala et al 2021).…”

Cadmium as an Endocrine Disruptor That Hinders the Reproductive and Developmental Pathways in Freshwater Fish: A Review

“…The exposure of freshwater biota to endocrine-disrupting metals like Cd can have significant implications for the population dynamics of affected fish species. Reduced fertility, skewed sex ratios, and altered reproductive behavior can lead to decreased population size and genetic diversity, which can have long-term effects on the survival and viability of a species [17]. Due to the crucial involvement of the endocrine system in regulating homeostasis and other physiological processes, the study of the effects of such a disruption may be significant.…”